Abstract
BACKGROUND: Monitoring lifestyle habits and physiological metrics are essential for improving cardiovascular outcomes and supporting recovery after acute cardiac events. Sleep is acknowledged as a core component of cardiovascular health and a predictive tool of adverse outcomes following acute myocardial infarction (AMI). OBJECTIVE: The present study aimed to assess sleep metrics and explore the links between sleep patterns, heart rate variability (HRV) parameters, and traditional cardiovascular risk factors in patients with AMI. METHODS: Sixty male patients with AMI (56.77 ± 8.24 years) participated in this study. Cardiac autonomic function was assessed with short-term HRV analysis during the second week post-AMI. Physical activity level was assessed using accelerometers. Sleep quality and quantity were evaluated objectively using a wrist-worn accelerometer and subjectively by the Pittsburgh Sleep Quality Index. Chronotype was evaluated with the Horne and Otsberg questionnaire. RESULTS: Twenty post-AMI patients (33.3%) tended to experience poor sleep quality, with a sleep efficiency inferior to 85%. Thirty patients (50%) experienced short sleep duration, 16 (26.7%) had a healthy sleep duration (7-8 h), and 14 (23.3%) slept more than 8 h. Multiple regression analysis revealed that patients with healthy sleep quality and quantity exhibited higher HRV parameters, both in time and frequency domain values (p < 0.05). Low physical activity level was observed in patients with long sleep duration (p = 0.005) and evening chronotype (p = 0.022). CONCLUSION: Patients who spent more time performing moderate to vigorous physical activity tended to exhibit good sleep health and increased parasympathetic activity which are considered cardioprotective after AMI. TRIAL REGISTRATION: PACTR202208834230748.